3‐Mercaptopyruvate sulfurtransferase supports endothelial cell angiogenesis and bioenergetics

Abstract

Background and Purpose During angiogenesis, quiescent endothelial cells (ECs) are activated by various stimuli to form new blood vessels from pre‐existing ones in physiological and pathological conditions. Many research groups have shown that hydrogen sulfide (H2S), the newest member of the gasotransmitter family, acts as a proangiogenic factor. To date, very little is known about the regulatory role of 3‐mercaptopyruvate sulfurtransferase (3‐MST), an important H2S‐producing enzyme in ECs. The aim of our study was to explore the potential role of 3‐MST in human EC bioenergetics, metabolism, and angiogenesis. Experimental Approach To assess in vitro angiogenic responses, we used EA.hy926 human vascular ECs subjected to shRNA‐mediated 3‐MST attenuation and pharmacological inhibition of proliferation, migration, and tube‐like network formation. To evaluate bioenergetic parameters, cell respiration, glycolysis, glucose uptake, and mitochondrial/glycolytic ATP production were measured. Finally, global metabolomic profiling was performed to determine the level of 669 metabolic compounds. Key Results 3‐MST‐attenuated ECs subjected to shRNA or pharmacological inhibition of 3‐MST significantly reduced EC proliferation, migration, and tube‐like network formation. 3‐MST silencing also suppressed VEGF‐induced EC migration. From bioenergetic and metabolic standpoints, 3‐MST attenuation decreased mitochondrial respiration and mitochondrial ATP production, increased glucose uptake, and perturbed the entire EC metabolome. Conclusion and Implications 3‐MST regulates bioenergetics and morphological angiogenic functions in human ECs. The data presented in the current report support the view that 3‐MST pathway may be a potential candidate for therapeutic modulation of angiogenesis. Linked Articles This article is part of a themed section on Hydrogen Sulfide in Biology & Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.4/issuetoc

Role of 3-Mercaptopyruvate Sulfurtransferase in the Regulation of Proliferation, Migration, and Bioenergetics in Murine Colon Cancer Cells

“…These effects may be either related to additional pharmacological actions of HMPSNE (unrelated to 3-MST inhibition) and/or may indicate that a small amount of H 2 S may be sufficient to exert various biological effects, and a near-complete or complete inhibition of all 3-MST-derived H 2 S production is necessary to exert full biological responses. The findings of the current study are in line with a recent paper testing the effect of HMPSNE in vascular endothelial cells, where the 3-MST inhibitor, in a similar concentration range of 30-100 µM suppressed cell proliferation, migration and-most significantly-the formation of tube-like structures [45]. We have also noted that while at 100 µM, the inhibitory effect of HMPSNE on MTT conversion was comparable at 24 h and 48 h, at 300 µM the inhibition at 24 h seemed to be more pronounced than at 48 h (Figure 7b vs.…”

“…(Nevertheless, H 2 S can S-sulfurate Cys-SOH and Cys-SNO to Cys-SSH [49]). Post-translational modifications of various mitochondrial or extramitochondrial 3-MST-derived H 2 S are likely follow a different time-course and concentration-response than some of the other biological effects elicited by H 2 S. Indeed, metabolomic analysis of HMPSNE-treated endothelial cells revealed many alterations in various biochemical pathways, the molecular mechanism of which are not yet fully understood [45]. The multitude of effects of H 2 S and polysulfides on various cellular targets may also explain some of the apparently conflicting findings between bioenergetic and functional responses reported in the current article.…”

“…In the context of tumor biology, we must emphasize that the role of 3-MST must be viewed not only within the tumor cell itself, but also in the tumor microenvironment. 3-MST is an enzyme that is expressed in vascular structures (and, indeed, it regulates endothelial cell proliferation, migration and angiogenesis [45]). 3-MST is also likely to be present in various immune cells [50], although its functional role (in general, or in particular with respect to tumor immunology) remains to be clarified in future studies.…”

“…The current studies identify 3-MST as the principal source of biologically active H 2 S in the murine colon cancer cell line CT26 and indicate that 3-MST-derived H 2 S is involved in the regulation of cell proliferation, migration and bioenergetics. We utilized the novel pharmacological 3-MST inhibitor HMPSNE and the present article is, in fact, one of the handful of recent studies [26,45,51] that utilizes this inhibitor (which, to date, appears to be the only 3-MST pharmacological inhibitor with sufficient potency and selectivity to enable cell-based studies). Using a live cell imaging assay, we have also directly demonstrated the inhibitory effect of HMPSNE on cellular H 2 S production.…”

Role of 3-Mercaptopyruvate Sulfurtransferase in the Regulation of Proliferation and Cellular Bioenergetics in Human Down Syndrome Fibroblasts

“…To address this question, we employed the recently discovered 3-MST inhibitor HMPSNE, which, to date, is the most potent and most selective pharmacological inhibitor of this enzyme [10,36]. HMPSNE has been successfully employed in cell-based studies in various cell types, at concentrations similar (or higher) [14,[37][38][39] than those used in the current project. Pharmacological inhibition of 3-MST in healthy control fibroblasts only had a slight effect on cellular bioenergetic parameters, but it reduced their proliferation rate.…”